Figure 1. Tissue-specific ERAD deficiency in the thyroid gland.

(A) Western blotting of Hrd1 and actin (gels at left) and quantitation (right) in the thyroid glands of Hrd1^control and Hrd1^TPO mice (n = 5 mice per group). (B) Serum thyroid-stimulating hormone (TSH) and total T₄ and T₃ levels of Hrd1^control and Hrd1^TPO mice (n = 11–12 mice per group). (C) Representative H&E images of thyroid glands from Hrd1^control and Hrd1^TPO mice (n = 5 mice per group). (D) Western blotting analysis of IRE1α, OS9, BiP, ERdj6, phosphorylated eIF2α (P-eIF2α), and total eIF2α (T-eIF2α) (gels at left) and quantification (normalized to actin; except phosphorylated eIF2α normalized to total eIF2α; bar graph at right) in the thyroid glands of Hrd1^control and Hrd1^TPO mice (n = 5 mice per group). (E) PCR revealing spliced and unspliced XBP1 mRNA as a readout of Ire1 activity (upper) and quantitation (bar graph below) in the thyroids of Hrd1^control and Hrd1^TPO mice (n = 4–6 mice group). (F) Transmission electron microscopy of Hrd1^control and Hrd1^TPO thyrocytes (white scale bars = 1 μm; n = 1–2 mice per group); the thyroid follicle lumen is seen at the lower left of each image; blue arrows point to distended ER. (G) Representative Western blotting analysis of full-length (FL) and cleaved (CL) PARP in the thyroid glands of Hrd1^control and Hrd1^TPO mice (n = 6 mice per group). (H) Representative TUNEL labeling (red, with DAPI counterstain in blue, images at left) and quantitation of the fraction of TUNEL-positive follicles (as a fraction of total follicles, right) shows negligible thyroid cell death in either genotype. Graphs in panels A, B, and D–F show mean ± SD; *P < 0.05, **P < 0.01, ****P < 0.0001 (unpaired 2-tailed Student’s t test); each dot represents an individual animal (squares = males; circles = females).